According to the poll released this week, 42 percent of respondents said the United States made "a mistake" in sending military forces to Afghanistan, up from 30 percent last month and just 6 percent in January 2002.

The US currently has some 38,000 troops deployed in Afghanistan, and plans to send 17,000 more soon. (See a map of the country here.) Mr. Obama made the comments on CBS's "60 Minutes" program. (See highlights here and full interview here.)

"What we're looking for is a comprehensive strategy [for Afghanistan]," President Obama told the CBS programme 60 Minutes on Sunday.

"There's got to be an exit strategy. There's got to be a sense that this is not a perpetual drift."

He also warned that the focus of US policy should remain on eliminating direct terrorist threats to the US: "Making sure that Al Qaeda cannot attack the US homeland and US interests and our allies. That's our number one priority."

Agence France-Presse highlighted Obama's remarks that the "decision last month to send 17,000 more US troops to Afghanistan – largely to head off a spike in violence before elections in August – was the most difficult he has had to make since taking office."

"You know I think it is the right thing to do. But it's a weighty decision because we actually had to make the decision prior to the completion of (the) strategic review that we were conducting," he said.

US commanders have said as many as 30,000 additional troops are needed to overcome a stalemate in parts of Afghanistan. But some analysts caution against a gradual Vietnam-like escalation in a country historically hostile to outsiders.

According to Reuters, in the past few days alone, a civilian contractor was killed and six wounded on Friday, two soldiers from the NATO-led force were killed in southern Afghanistan Sunday, and Taliban insurgents killed eight policemen on patrol Monday.

NATO troops killed an insurgent leader on Saturday and detained three suspected militants, the same report said. Voice of America reports that nine of the insurgent leader's "associates" were also killed.

The Washington Post reported Sunday on the first demonstration in Washington since Obama took office, which included calls to pull troops out of Afghanistan. Thousands of protesters, some bearing "mock coffins" to protest war casualties, took to the streets on the sixth anniversary of the war in Iraq.

The report quoted protesters who are wary of Obama's plans in Afghanistan.

"I came from Pittsburgh today because I think the war in Iraq was a disastrous mistake, and I really hope this administration doesn't make a similar mistake in Afghanistan," said Robin Alexander ... who works for a labor union.

"He's really on the wrong track with not getting out of Iraq more quickly and escalating in Afghanistan," said Pennsylvanian Al Hart, 58. "I think this is going to be his Vietnam if he doesn't change course."

The Associated Press reports the Washington protests were part of a coordinated "Day of Action" that included similar rallies in Los Angeles and San Francisco. In San Francisco, the rally "turned ugly when a large group of protesters started throwing sticks and water bottles at police," and several protesters were detained.

Many [protesters] said they were disappointed by the increased troop deployment to Afghanistan.

"He has withdrawn troops from Iraq, and that's great, but he's still leaving tens of thousands there and moving more into Afghanistan," said Kristin Lubbert of San Francisco.

Xinhua news agency reported on a similar protest in Los Angeles on Saturday, saying thousands marched down Hollywood Boulevard to call for all US troops to be brought home.

Marie Shrupsolv ... told Xinhua: "We are against what is going on now. We are against the illegal occupation of Iraq and don't want Obama to go into Afghanistan. We are for peace and do not want America to go around the world to kill innocent people. The invasion of Iraq was illegal."

She added that those who started the war should be prosecuted for their war crimes.

This Russmocartoon from 2005 shows one cartoonist's answer to what the Afghanistan "exit strategy" should be.